The game is good, the gameplay is okay; it could do with some more work like more upgrades. The arts is good with the screenshake and postprocessing, the only thing is that you might consider picking a colorpallete to make the colors more consistent an pleasing for the eye. Maybe draw the sprites in the same style, I noticed that some of the art is in pixelart and some not. Make an option where you can toggle the postprocessing and the screenshake separetely, I looked in the inspector console and it told me that there is some bug with something to do with the postprocesing in the game, not in the main menu (something to do with my graphics card drivers or with Linux).

Good game overall! Add a credit for me in-game lol. /Mhiw